How many CFU should a daily probiotic have? Doses used in studies
There is no single right number. Here is what NIH says about typical counts, and the doses used in studies of the strains in one real product.
- 1 to 10BCFU per dose in many probiotic supplements
- 50B+CFU in some products; higher is not necessarily more effective
- 1 to 20BCFU a day in the single-strain studies Physician's Choice cites
B = billion. Sources: NIH Office of Dietary Supplements; Physician's Choice strain dossier.
Published by Physician's Choice, which makes the products discussed on this site.
The CFU scale
Where common label counts and study doses sit. The marks are labels, not recommendations.
How to read it- 1 to 10 billion per doseWhere NIH says many probiotic supplements sit.NIH Office of Dietary Supplements
- 50 billion or moreSome products, per NIH. Higher counts are not necessarily more effective.NIH Office of Dietary Supplements
- Study doses: 1, 2, 17 and 20 billionDaily doses used in studies of single strains in 60 Billion Probiotic.Physician's Choice strain dossier
- 60 Billion Probiotic60 billion CFU per capsule on the label, counted at expiration per the strain dossier.Printed label and strain dossier
60 Billion and 100 Billion, label by label
Each 60 Billion Probiotic entry comes from the printed label, the product page and the strain dossier, checked Sep 28, 2026, and names its source. There is no winner column.
| Label entry |  60 Billion Probiotic |
 100 Billion Probiotic |
|---|---|---|
| CFU per capsule | 60 billionLabel | Label being confirmedThe 100 Billion Probiotic label is being confirmed with Physician's Choice, and until it is, its entries stay off this table. See the current label on physicianschoice.com. |
| When CFU is counted | At expiration, per the strain dossier, which also says extra CFU is packed in at the factoryDossier | |
| Number of strains | 10Label | |
| Strain codes | Lc-11, La-14, Lpc-37, Ls-33, Lp-115, Bl-04, Bb-06, Bl-05, Bb-18, Lb-87 (the printed label lists species only)Dossier and product page | |
| Probiotic blend | 220 mgLabel | |
| Prebiotic blend | 150 mg: organic inulin (Jerusalem artichoke), organic acacia fiber, organic inulin (chicory)Label | |
| Serving | 1 capsule a day, with or without food; 30 servings per bottleLabel and product page | |
| Capsule | Acid-resistant vegetable capsule (hypromellose, gellan gum)Product page | |
| Storage | No refrigeration; store cool and dryProduct page |
100 Billion Probiotic is left out of this table until Physician's Choice confirms its label.
Choosing between the two counts: Is a 100 billion CFU probiotic better than a 60 billion CFU probiotic?
Answers
Nine answers are out. One more waits on the 100 Billion Probiotic label.
Published Oct 6, 2026. 4 min read.
How many CFU should a daily probiotic have? Doses used in studies
NIH ranges, study doses by strain, and how to read the CFU line on a label.
Published Oct 8, 2026. 8 min read.
Is a 100 billion CFU probiotic better than a 60 billion CFU probiotic?
What NIH, ISAPP and the 2023 WGO guideline say about higher counts, and a table for choosing.
Published Oct 9, 2026. 10 min read.
What does CFU mean on a probiotic label?
What a colony forming unit is, why labels print milligrams and CFU, and how the count date changes the number.
Published Oct 10, 2026. 6 min read.
Can you take probiotics with antibiotics? Timing, spacing and what to ask
How many hours apart, which comes first, why yeast probiotics differ, and what to ask a pharmacist.
Published Oct 10, 2026. 8 min read.
Can you take too many probiotics? Doubling up, symptoms and limits
Whether any source sets an upper limit, the mild symptoms sources describe, and what to check when you take two products or a capsule plus yogurt.
Published Oct 15, 2026. 8 min read.
What is the strongest probiotic? What "strong" can mean on a label
No standard defines it. What CFU, strain counts, survival to the date, "high potency" and strain evidence each tell you.
Published Oct 16, 2026. 8 min read.
How do probiotics work? What happens after you swallow one
What a probiotic does in the gut, whether it survives stomach acid, whether it settles in, and how long it stays after the last dose.
Published Oct 16, 2026. 8 min read.
What is Bifidobacterium? The species on probiotic labels, and what was studied
The genus, the five species on labels, how B. lactis and B. animalis relate, and what single-strain studies measured.
New. Published Oct 18, 2026. 9 min read.
What are spore-based probiotics? Bacillus on the label, new names and safety
What a spore is, the Bacillus species on labels and their new genus names, how spores are counted, and what Europe's safety list says.
Planned, waiting on the label
100 Billion Probiotic label, entry by entry
Three terms on every label
Read these before you compare any two numbers.
- CFU
- Colony forming units. A lab count of live microbes that can grow.
- At manufacture or at expiration
- Labels count CFU on one of two dates. NIH notes that some experts recommend the count by the expiration date.
- Per capsule or per serving
- A serving can be more than one capsule. Check the serving size first.
Source: NIH Office of Dietary Supplements, probiotics fact sheet for consumers. All three terms in full: What does CFU mean on a probiotic label?
Where to buy
Physician's Choice makes both products discussed here and sells them on its own site.
See both on physicianschoice.com